TW201739900A - Etching solution capable of suppressing particle appearance - Google Patents

Abstract

The present disclosure relates to an etching solution capable of suppressing particle appearance including a first silane compound in which three or more hydrophilic functional groups are independently bonded to a silicon atom and a second silane compound in which one or two hydrophilic functional groups are independently bonded to a silicon atom.

Description

An etching solution capable of suppressing the appearance of particles

The present invention relates to an etching solution capable of suppressing the occurrence of ruthenium-based particles after the ruthenium nitride etching is completed.

The use of phosphoric acid as an etchant for a tantalum nitride layer is a well-known method.

When pure phosphoric acid is used, high selectivity is impossible because phosphoric acid etches both tantalum nitride and ruthenium oxide. Therefore, problems such as defects, pattern abnormalities, and occurrence of particles occur in the etching process.

At the same time, attempts were made to use a fluorine-containing compound as an additive to further increase the etching rate of the tantalum nitride layer. However, fluorine also increases the etch rate of the tantalum nitride layer.

In recent years, an antimony additive has been added to phosphoric acid to reduce the hafnium oxide layer to achieve high selectivity. Since the solubility of a decane compound mainly used as an antimony additive to an etching solution including phosphoric acid is low, a decane compound in which a hydrophilic functional group (for example, a group capable of bonding hydrogen) is bonded to a ruthenium atom to increase a decane compound in phosphoric acid is used. Solubility in solution.

When a functional group is present in the decane, the solubility of the compound will increase in the phosphoric acid; therefore, proper solubility of the decane compound to the etching solution can be ensured. However, when the concentration of the decane compound in the etching solution is increased to suppress the cerium oxide E/R (etching rate), the selectivity is lowered since the cerium nitride E/R is also suppressed.

In addition, if too much antimony additive is used, the antimony additives will combine to produce uncontrollable subtle results, resulting in wafer and particle bonding, resulting in wafer defects.

It is an object of the present disclosure to provide an etching solution for a tantalum nitride layer which can improve the selectivity of a tantalum nitride layer with respect to a ruthenium oxide layer by using a ruthenium compound-based ruthenium additive.

Another object of the present disclosure is to provide an etching solution for a tantalum nitride layer that can compensate for a reduced etching rate due to the use of a cerium additive by using a fluorine-containing compound.

The objects of the present disclosure are not limited to the above objects, and other objects and advantages will be understood by those skilled in the art from the following description. In addition, it will be readily understood that the objects and advantages of the present disclosure can be implemented by the means described in the appended claims and combinations thereof.

According to an aspect of the present disclosure, an etching solution for a tantalum nitride layer includes: an aqueous solution containing at least one of an inorganic acid and an organic acid; a first decane compound containing 1-6 germanium atoms, at least one of which is ruthenium The atom is bonded to three or more hydrophilic functional groups; a second decane compound containing 1-6 ruthenium atoms, wherein the number of hydrophilic functional groups bonded to one ruthenium atom is at most 2; and a fluorine-containing compound.

The hydrophilic functional group may be a hydroxyl group or a functional group which may be substituted with a hydroxyl group under the pH condition of an etching solution capable of suppressing the occurrence of particles.

In accordance with another aspect of the present disclosure, a post-eching cleaning solution is provided that reduces or inhibits the occurrence of ruthenium-based particles upon cleaning after etching the ruthenium substrate with an etch solution comprising a ruthenium additive.

The above objects, features and advantages will be apparent from the detailed description. The detailed description of the embodiments enables those skilled in the art to readily implement the technical idea of the present disclosure. Detailed descriptions of well-known functions or constructions may be omitted to avoid unnecessarily obscuring the gist of the present disclosure. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to refer to the same elements.

According to an exemplary embodiment of the present disclosure, an etching solution for a tantalum nitride layer may include: an aqueous solution including at least one of an inorganic acid and an organic acid (hereinafter referred to as an acidic aqueous solution), containing 1-6 germanium atoms a first decane compound in which at least one ruthenium atom is bonded to three or more hydrophilic functional groups, a second decane compound containing 1-6 ruthenium atoms, wherein the number of hydrophilic functional groups bonded to one ruthenium atom Up to 2, and fluorochemicals.

The inorganic acid may be at least one selected from the group consisting of sulfuric acid, nitric acid, phosphoric acid, citric acid, hydrofluoric acid, boric acid, hydrochloric acid, and perchloric acid. Further, in addition to the above inorganic acid, phosphoric anhydride, pyrophosphoric acid or polyphosphoric acid can be used.

The organic acid may be at least one selected from the group consisting of acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, tartaric acid, and hydrogen carbonic acid. Further, in addition to the above organic acid, organic acids such as propionic acid, butyric acid, palmitic acid, stearic acid, oleic acid, malonic acid, succinic acid, maleic acid, glycolic acid, glutaric acid, and hexamethylene may be used. Acid, sulfosuccinic acid, valeric acid, caproic acid, capric acid, lauric acid, myristic acid, lactic acid, malic acid, citric acid, tartaric acid, benzoic acid, salicylic acid, p-toluenesulfonic acid, naphthoic acid, nicotinic acid , toluic acid, anisic acid, phthalic acid and citric acid. If necessary, acid water soluble containing a mixed acid of a mineral acid and an organic acid can be used. liquid.

The inorganic acid and the organic acid may be present in the form of a salt in an aqueous solution, and the salt is preferably in the form of an ammonium salt.

The acidic aqueous solution is a component that maintains the pH of the etching solution to suppress the various decane compounds present in the etching solution from becoming cerium-based particles.

In an exemplary embodiment, the content of the acidic aqueous solution is preferably from 60 to 90 parts by weight based on 100 parts by weight of the etching solution capable of suppressing the occurrence of particles.

When the content of the acidic aqueous solution is less than 60 parts by weight based on 100 parts by weight of the etching solution capable of suppressing the occurrence of particles, the etching rate of the tantalum nitride layer may be lowered, and thus, the tantalum nitride layer may not be sufficiently etched, or may be lowered The process efficiency of etching the tantalum nitride layer.

On the other hand, when the content of the acidic aqueous solution is more than 90 parts by weight based on 100 parts by weight of the etching solution capable of suppressing the occurrence of particles, it is possible not only to excessively increase the etching rate of the tantalum nitride layer but also because the tantalum oxide layer is rapidly etched, Therefore, it is also possible to reduce the selectivity of the tantalum nitride layer relative to the ruthenium oxide layer. In addition, when the ruthenium oxide layer is etched, defects of the ruthenium substrate may be caused.

According to an exemplary embodiment of the present disclosure, the etching solution capable of suppressing the occurrence of particles includes the first decane compound represented by the following Chemical Formula 1 or Chemical Formula 2 to increase the selectivity of the cerium nitride layer with respect to the cerium oxide layer.

As shown in the following Chemical Formula 1, the first decane compound of the present disclosure may be defined as a compound in which a functional group of R1 to R4 is bonded to one ruthenium atom. Wherein at least three of R ₁ to R ₄ are hydrophilic functional groups.

[Chemical Formula 1]

In Chemical Formula 1, R ₁ to R ₄ are each independently a hydrophilic functional group, or are selected from hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, C ₂ - containing at least one hetero atom. C ₁₀ heteroalkyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aralkyl a functional group of a decyloxy group and a decane.

Further, as shown in the following Chemical Formula 2, the first decane compound of the present disclosure may be defined as a decane compound in which at least two ruthenium atoms are continuously bonded:

In Chemical Formula 2, R ₅ to R ₁₀ are each independently a hydrophilic functional group, or are selected from hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, C ₂ - containing at least one hetero atom. C ₁₀ heteroalkyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aralkyl a functional group of a decyloxy group and a decane, and n is an integer of 1 to 5.

That is, the first decane compound contains 1 to 6 germanium atoms, and specifically contains at least one germanium atom bonded to three or more hydrophilic functional groups, thereby ensuring cerium nitride for inclusion in an acidic aqueous solution. The layer has sufficient solubility in the etching solution and can form a strong hydrophilic interaction with the ruthenium substrate, particularly the ruthenium oxide layer.

The first decane compound attached to the surface of the ruthenium oxide layer by a strong hydrophilic interaction can prevent the ruthenium substrate from being etched by the inorganic acid or fluorine-containing compound of the ruthenium oxide layer.

Under the pH condition of the acidic aqueous solution, the hydrophilic functional group bonded to the ruthenium atom is a hydroxyl group or a functional group which may be substituted by a hydroxyl group.

Non-limiting examples of functional groups in which a hydroxyl group may be substituted under acidic pH conditions include an amino group, a halogen group, a sulfonic acid group, a phosphonic acid group, a phosphoric acid group, a thiol group, an alkoxy group, Amidino, ester, anhydride, oxime, cyano, carboxyl and azole. Therefore, the functional group which may be substituted with a hydroxyl group under the pH condition of the acidic aqueous solution is not necessarily limited to the above functional group, and is understood to include any functional group which may be substituted with a hydroxyl group under the pH condition of the acidic aqueous solution.

The pH condition of the acidic aqueous solution in the present disclosure is 4 or less. When the pH condition of the acidic aqueous solution is more than 4, the stability of the first decane compound present in the etching solution capable of suppressing the occurrence of particles may be lowered due to a higher pH, and therefore, the decane compound may serve as a source of ruthenium-based particles.

Halogen in the present disclosure means fluorine (-F), chlorine (-Cl), bromine (-Br) or iodine (-I), and haloalkyl means an alkyl group substituted by the above halogen. For example, halomethyl refers to methyl (-CH ₂ X, -CHX ₂ or -CX ₃ ) wherein at least one hydrogen of the methyl group is replaced by a halogen.

Further, the alkoxy group in the present disclosure means an -O-(alkyl) group and an -O-(unsubstituted cycloalkyl) group, and has one or more ether groups and 1-10 a linear or branched hydrocarbon of one carbon atom.

Specifically, the alkoxy group includes a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a n-butoxy group, a t-butoxy group, a sec-butoxy group, a n-pentyloxy group, a n-hexyloxy group, and 1, 2-dimethylbutoxy group, cyclopropoxy group, cyclobutoxy group, cyclopentyloxy group, cyclohexyloxy group or the like, but is not limited thereto.

When R _a (wherein a is an integer selected from 1 to 4) is an alkenyl group or an alkynyl group, the sp ² -hybridized carbon of the alkenyl group or the sp-hybridized carbon of the alkynyl group may be directly bonded or may be bonded sp alkyl bonded ³ - sp- hybridized carbon on indirectly hybridized carbon alkenyl group bonded to an sp ² hybrid on carbon or alkynyl group.

The C _a -C _b functional group herein refers to _a functional group having a carbon atom of ab. For example, C _a -C _b alkyl means a saturated aliphatic group including a straight-chain alkyl group and a branched alkyl group in which the number of carbon atoms is ab. The linear alkyl group or the branched alkyl group has 10 or less carbon atoms in the main chain (for example, a C ₁ -C ₁₀ linear chain, a C ₃ -C ₁₀ branch), preferably 4 or less, More preferably 3 or less.

Specifically, the alkyl group may be methyl, ethyl, n-propyl, isopropyl, n-butyl, butyl, isobutyl, tert-butyl, pent-1-yl, pentan-2-yl, pentyl 3-yl, 3-methylbut-1-yl, 3-methylbut-2-yl, 2-methylbut-2-yl, 2,2,2-trimethyleth-1-yl, N-hexyl, n-heptyl and n-octyl.

As used herein, unless otherwise defined, an aryl group, includes a monocyclic or polycyclic (preferably one to four ring) unsaturated aryl ring which is conjugated or covalently bonded to each other. Non-limiting examples of aryl groups include phenyl, biphenyl, ortho-terphenyl, m-terphenyl, p-terphenyl, 1-naphthyl, 2-naphthyl, 1-indenyl, 2-indenyl, 9-fluorene Base, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, 1-indenyl, 2-indenyl and 4-indenyl.

As used herein, heteroaryl refers to a functional group wherein one or more carbon atoms of the aryl group as defined above are substituted with a non-carbon atom such as nitrogen, oxygen or sulfur.

Non-limiting examples of heteroaryl groups include furyl, tetrahydrofuranyl, pyrrolyl, pyrrolidinyl, thienyl, tetrahydrothiophenyl, oxazolyl, isoxazolyl, triazolyl, thiazolyl, isothiazolyl, Pyrazolyl, pyrazolidinyl, oxadiazolyl, thiadiazolyl, imidazolyl, imidazolinyl, pyridyl, pyridazinyl, triazinyl, acridinyl, morpholinyl, thiomorpholinyl , pyrazinyl, acridinyl, pyrimidinyl, naphthyridinyl, benzofuranyl, benzothienyl, indolyl, anthracene Indolynyl, pyridazinyl, oxazolyl, quinazolyl, quinolinyl, isoquinolinyl, porphyrinyl, pyridazinyl, quinazolinyl, quinoxalinyl, pteridine, quin N-cycloalkyl, carbazolyl, acridinyl, phenazinyl, phenothiazine, phenoxazinyl, fluorenyl, benzimidazolyl, benzothiazolyl, and the like, and analogs conjugated therewith.

The aralkyl group used herein is a functional group in a form in which an aryl group is substituted by a carbon of an alkyl group, and has a formula of -(CH ₂ ) _n Ar. Examples of the aralkyl group include a benzyl group (-CH ₂ C ₆ H ₅ ) or a phenethyl group (-CH ₂ CH ₂ C ₆ H ₅ ) and the like.

Unless otherwise defined, a hydrocarbon ring (hereinafter referred to as a cycloalkyl group) or a hydrocarbon ring containing a hetero atom (hereinafter referred to as a heterocycloalkyl group) as used herein is understood to mean a cyclic structure of an alkyl group or a heteroalkyl group, respectively. structure.

Non-limiting examples of cycloalkyl groups include cyclopentyl, cyclohexyl, 1-cyclohexenyl, 3-cyclohexenyl, cycloheptyl, and the like.

Non-limiting examples of heterocycloalkyl groups include 1-(1,2,5,6-tetrahydropyridyl), 1-acridinyl, 2-acridinyl, 3-acridinyl, 4-morpholinyl 3-morpholinyl, tetrahydrofuran-2-yl, tetrahydrothiophen-2-yl, tetrahydrothiophen-3-yl, 1-pyridazinyl, 2-pyridazinyl and the like.

Further, a cycloalkyl or heterocycloalkyl group may be conjugated to another cycloalkyl group, another heterocycloalkyl group, an aryl group or a heteroaryl group, or may be covalently bonded thereto.

The carbaryloxy group used herein is a functional group in a form in which a methoxyalkyl group is substituted by oxygen, and has a formula -O-Si(R) ₃ .

In the etching solution for the tantalum nitride layer, the first germane compound is preferably from 100 to 10,000 ppm.

When the first decane compound in the etching solution capable of suppressing the occurrence of particles is small The effect of increasing the selectivity of the tantalum nitride layer relative to the ruthenium oxide layer may be insufficient in the presence of 100 ppm. On the other hand, when the first decane compound in the etching solution capable of suppressing the occurrence of particles is more than 10,000 ppm, the etching rate of the tantalum nitride layer may be correspondingly lowered according to an increased yttrium concentration in the etching solution capable of suppressing the occurrence of particles, and The first decane compound itself can serve as a source of sulfhydryl particles.

According to an exemplary embodiment of the present disclosure, an etching solution capable of suppressing the occurrence of particles may include a first decane compound as a cerium additive to compensate for a decrease in an etching rate of the cerium nitride layer, and may also include a fluorine-containing compound to improve The efficiency of the overall etching process.

As used herein, a fluorochemical refers to any type of compound capable of dissociating fluoride ions.

In an exemplary embodiment, the fluorine-containing compound is at least one selected from the group consisting of hydrogen fluoride, ammonium fluoride, ammonium difluoride, and ammonium hydrogen fluoride.

Further, in another exemplary embodiment, the fluorine-containing compound may be a compound in which an organic cation and a fluorine-based anion are ionically bonded.

For example, the fluorine-containing compound may be a compound in which an alkylammonium and a fluorine-based anion are ionically bonded. Wherein the alkylammonium is an ammonium having at least one alkyl group and may have up to four alkyl groups. Alkyl groups are as defined above.

As another example, the fluorine-containing compound may be an ionic liquid in which an organic cation and a fluorine-based anion are ionically bonded, and the organic cation is selected from the group consisting of alkylpyrroleium, alkylimidazolium, alkylpyrazolium, alkyloxazolium , alkyl thiazolium, alkyl pyridinium, alkyl pyrimidine, alkyl pyridazin, alkyl pyrazinium, alkyl pyrrolidinium, alkyl hydrazine, alkyl morpholinium and alkyl acridine, And a fluoro anion selected from the group consisting of fluorophosphates, fluoroalkyl fluorophosphates, fluoroborates, and fluoroalkyl groups Fluoroborate.

The fluorine-containing compound provided in the form of an ionic liquid has a high boiling point and a high decomposition temperature as compared with hydrogen fluoride or ammonium fluoride which is generally used as a fluorine-containing compound in an etching solution capable of suppressing the occurrence of particles. Therefore, there is an advantage in that it is not necessary to pay attention to changing the composition of the etching solution due to decomposition in the etching process performed at a high temperature.

However, when excessive fluorine or fluorine ions remain in the etching solution due to the excessive fluorine compound contained in the etching solution capable of suppressing the occurrence of particles, the etching rate of the tantalum nitride layer and the etching rate of the hafnium oxide layer can be improved.

According to the present disclosure, the second decane compound represented by Chemical Formula 3 or 4 is additionally included in an etching solution capable of suppressing the occurrence of particles, and thus the problem of an increase in the etching rate of the cerium oxide layer caused by the fluorine-containing compound can be suppressed.

As shown in the following Chemical Formula 3, the second decane compound of the present disclosure may be defined as a compound in which a functional group of R ₁₁ to R ₁₄ is bonded to one ruthenium atom. The number of hydrophilic functional groups in R ₁₁ to R ₁₄ is 1-2.

In Chemical Formula 3, R ₁₁ to R ₁₄ are each independently a hydrophilic functional group, or are selected from hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, C ₂ - containing at least one hetero atom. C ₁₀ heteroalkyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aralkyl a functional group of a decyloxy group and a decane.

Further, as shown in the following Chemical Formula 4, the second decane compound of the present disclosure may be defined as a decane compound in which at least two ruthenium atoms are continuously bonded:

In Chemical Formula 4, R ₁₅ to R ₂₀ are each independently a hydrophilic functional group, or are selected from hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, C ₂ - containing at least one hetero atom. C ₁₀ heteroalkyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aralkyl a functional group of a decyloxy group and a decane, and n is an integer of 1 to 5.

That is, the second decane compound contains 1 to 6 germanium atoms and contains a hydrophilic functional group bonded to the ruthenium atom, thereby ensuring an appropriate solubility level in an etching solution including an acidic aqueous solution capable of suppressing the occurrence of particles.

Therefore, the second decane compound existing in an appropriately dissolved state in the etching solution capable of suppressing the occurrence of particles can be appropriately reacted with the fluorine-containing compound excessively contained with respect to the first decane compound, thereby preventing the etching rate of the cerium oxide layer. increase.

Further, the number of hydrophilic functional groups of the second decane compound is smaller than that of the first decane compound, and thus the possibility of being a core of the ruthenium-based particles can be minimized.

In particular, the second decane compound has a maximum of two hydrophilic functional groups to ensure solubility in an etching solution capable of suppressing the occurrence of particles, thereby having up to two fluorene hydroxyl groups (-Si-OH) under the pH condition of the acidic aqueous solution.

Where the second decane compound has up to two hydrophilic functional groups Ming means that the number of hydrophilic functional groups bonded to one ruthenium atom is at most two. Further, in order to secure solubility in the etching solution for the tantalum nitride layer, it is preferred that the second germane compound has at least one hydrophilic functional group.

Therefore, when there is one germanium atom forming the second germane compound, it is preferred that the number of hydrophilic functional groups in the four functional groups bonded to the germanium atom is one or two. Further, when the number of ruthenium atoms forming the second decane compound is 2 or more, it is preferred to include at least one ruthenium atom bonded to at most two hydrophilic functional groups.

Wherein, in the acidic aqueous solution at a pH, when the hydrophilic functional group in the second decane compound is substituted with a hydrazine hydroxyl group (-Si-OH), the second decane compound and the first decane compound or the second decane compound pass through the hydrazine hydroxy group (- The Si-OH) is polymerized to grow into a silicone dimer, an anthrone ketone oligomer or an eucalyptus oil having a regular one-dimensional or two-dimensional arrangement, and thus, the occurrence of sulfhydryl particles due to random growth can be prevented in advance.

In the etching solution for the tantalum nitride layer, the second germane compound is preferably from 100 to 30,000 ppm.

When the second decane compound is present in a concentration of less than 100 ppm in an etching solution capable of suppressing the occurrence of particles, it may be difficult to suppress etching of the ruthenium oxide layer by the fluorine-containing compound present in an excessive amount, and it may be difficult to suppress the first decane by the first decane The presence of ruthenium-based particles caused by the compound.

As described above, the etching solution capable of suppressing the occurrence of particles according to the present disclosure can maintain high selectivity of the tantalum nitride layer with respect to the ruthenium oxide layer, and at the same time can control the occurrence of ruthenium-based particles during etching or post-etch cleaning.

Therefore, when used at 165 ° C, it is possible to suppress particle out according to the present disclosure. When the etching solution is used to etch the tantalum nitride layer for 1 minute, the average diameter of the ruthenium-based particles which appear may be 0.1 μm or less.

According to another aspect of the present disclosure, there is provided an post-etch cleaning solution capable of reducing or suppressing the occurrence of ruthenium-based particles upon cleaning after etching a ruthenium substrate (wafer) with an etching solution including a ruthenium additive.

More specifically, the post-etching cleaning solution according to an exemplary embodiment of the present disclosure may include an acidic aqueous solution and a second decane compound represented by Chemical Formula 3 or 4. Unless otherwise defined, the definitions of the acidic aqueous solution and the second decane compound are the same as those defined in the etching solution capable of suppressing the occurrence of particles.

The acidic aqueous solution is a component which removes the ruthenium-based particles in a nanometer unit during the etching, and at the same time, inhibits the decane compound present in the cleaning solution from becoming a ruthenium-based particle by maintaining the pH of the cleaning solution.

Further, at the time of cleaning after etching the ruthenium substrate with an etching solution including a ruthenium additive, the acid in the acidic aqueous solution may dissolve or disperse various contaminants (including nano-sized ruthenium-based particles) present in the ruthenium substrate. Therefore, when secondary cleaning is performed using deionized water or the like, various contaminants can be easily removed from the crucible substrate after once cleaning the crucible substrate with the cleaning solution.

In an exemplary embodiment, the content of the acidic aqueous solution is preferably from 60 to 95 parts by weight based on 100 parts by weight of the cleaning solution.

When the content of the acidic aqueous solution is less than 60 parts by weight based on 100 parts by weight of the cleaning solution, since the pH of the cleaning solution is increased, the cerium-based additive used in the etching liquid remaining on the ruthenium substrate after the etching exhibits ruthenium-based particles, and It is therefore possible to reduce the efficiency of the cleaning process.

On the other hand, when the content of the acidic aqueous solution is more than 95 parts by weight based on 100 parts by weight of the cleaning solution, the viscosity of the acidic aqueous solution may be too high, and thus the fluidity of the cleaning solution may be lowered. When the fluidity of the acidic aqueous solution is lowered, the efficiency of the cleaning process may be lowered or the surface of the crucible substrate may be damaged. For example, surface damage of the ruthenium substrate may include pattern defects or the like due to etching of the ruthenium oxide layer.

Further, the moisture content in the acidic aqueous solution is preferably 40% by weight or less, more preferably 5% to 15% by weight.

When the water content in the acidic aqueous solution is more than 40% by weight, the cerium-based additive used in the etching solution remaining on the cerium substrate may exhibit cerium-based particles due to an increase in the pH of the cleaning solution. On the other hand, when the water content in the acidic aqueous solution is less than 5% by weight, not only the fluidity of the cleaning solution may be lowered, but also the ruthenium substrate may be excessively etched because the ruthenium substrate is etched by the cleaning solution.

Further, the pH of the acidic aqueous solution containing a mineral acid and/or an organic acid is preferably 4 or less.

When the pH of the acidic aqueous solution is more than 4, since the water content contained in the cleaning solution is excessive and the pH is high, the cerium-based particles may be present from the cerium additive used in the etching solution remaining on the cerium substrate.

The second decane compound represented by Chemical Formula 3 or 4 has a form in which at least one or at most two hydrophilic functional groups are bonded to one ruthenium atom, and solubility in a cleaning solution including an acidic aqueous solution can be sufficiently ensured.

Further, the second decane compound represented by Chemical Formula 3 or 4 has a maximum of two hydrophilic functional groups, and thus the decane compound itself is hardly used as a source of sulfhydryl particles during washing. may.

At a pH of an acidic aqueous solution, a second decane compound having at most two hydrazine hydroxy groups (-Si-OH) is polymerized with a hydrazine hydroxy group (-Si-OH) present in sulfhydryl particles having a size of several nanometers. The ruthenium-based particles are present on the ruthenium substrate after etching to produce a ruthenium-oxane compound.

Wherein, unlike the second decane compound represented by Chemical Formula 3 or 4, when the number of hydrophilic functional groups bonded to the ruthenium atom forming the decane compound is 3 or more (for example, the first decane compound), and when decane having a ruthenium hydroxy group When a compound is polymerized with a ruthenium-based particle having a size of several nanometers, random growth can be achieved due to the large number of polymerizable functional groups. Therefore, there is a risk that micron-sized cerium-based particles may occur.

Therefore, as shown in Chemical Formula 3 or Chemical Formula 4, according to various embodiments of the present disclosure, the second decane compound used in the cleaning solution replaces the hydroxy group bonded to the ruthenium particles present in the cleaning solution with a decyloxy group, which The form is such that no further polymerization can occur when cleaning the crucible substrate after etching. Therefore, the ruthenium-based particles can be prevented from growing and being precipitated into micron-sized ruthenium-based particles.

The concentration of the second decane compound in the cleaning solution is preferably from 100 to 5,000 ppm.

When the second decane compound in the cleaning solution is present at less than 100 ppm, the nano-sized cerium-based particles are inhibited from growing into micron-sized cerium-based particles during the cleaning process performed after etching the ruthenium substrate with the etching solution containing the cerium additive. The effect may be insufficient.

On the other hand, when the second decane compound in the cleaning solution is present in excess of 5,000 ppm, there is a problem that the decane compound is difficult to be sufficiently dissolved in the cleaning solution.

As described above, the decane compound present in the cleaning solution can suppress the growth mechanism of the ruthenium-based particles upon cleaning after etching the ruthenium substrate with an etching solution including a ruthenium additive. Therefore, the growth and precipitation of the ruthenium-based particles when the ruthenium substrate is cleaned after the etching can be prevented by using the cleaning solution according to the present disclosure.

As a result, defects in the ruthenium substrate and/or device caused by the ruthenium-based particles may be reduced.

Further, when the cleaning solution according to the present disclosure is used, that is, etching the ruthenium substrate using an etching solution including a ruthenium additive, the occurrence of ruthenium-based particles at the time of cleaning can also be reduced or suppressed, and thus, the composition of the etching solution can be more easily designed. . That is, there is no need to use other expensive additives as an alternative to the anthrone additive.

In accordance with another aspect of the present disclosure, a method of cleaning a substrate after etching that reduces or inhibits the occurrence of ruthenium-based particles upon cleaning after etching the ruthenium substrate with an etch solution comprising a ruthenium additive is provided.

More specifically, the method of cleaning a substrate after etching according to an exemplary embodiment of the present disclosure includes a preliminary cleaning step of preliminarily cleaning a substrate etched with an etching solution including a cerium additive with a cleaning solution, and a second cleaning step, that is, using water The substrate that was initially cleaned was cleaned twice.

The method of cleaning a substrate according to an exemplary embodiment of the present disclosure is based on the premise that the ruthenium substrate is etched with an etching solution including a ruthenium additive.

According to the present disclosure, the etched substrate is subjected to preliminary cleaning with an acidic aqueous solution including a second decane compound, and thus, the hydrazine hydroxy group is substituted with a decyloxy group in a form in which further polymerization is unlikely to occur, thereby preventing sulfhydryl particle growth and Precipitated into micron-sized sulfhydryl grain.

The temperature of the cleaning solution at the time of preliminary cleaning of the etched substrate is preferably from 70 to 160 °C.

Usually, the temperature of the etching solution for etching is 150 ° C or more. Therefore, when the temperature of the cleaning solution at the time of preliminary cleaning is lower than 70 ° C, the base of the crucible may be damaged due to a rapid change in the temperature of the crucible base. In addition, when the temperature of the cleaning solution at the time of preliminary cleaning exceeds 160 ° C, the crucible substrate may be damaged by overheating.

Subsequently, the initially cleaned substrate is washed twice with water (e.g., deionized water) to remove various contaminants from the crucible substrate.

The temperature of the water during the secondary cleaning of the initially cleaned substrate is preferably from 25 to 80 °C.

In the following, specific embodiments of the present disclosure will be provided. It should be noted that the embodiments to be described below are provided only for the purpose of specifically illustrating or explaining the present disclosure, and thus the present disclosure is not limited to the following embodiments.

Experimental Example 1. Data for inhibiting the growth of cerium oxide particles

Example

The composition of the etching solution for the tantalum nitride layer according to the embodiment is shown in Table 1 below.

Each of the etching solutions for the tantalum nitride layer according to Examples 1 to 8 includes 85% by weight of phosphoric acid and 15% by weight of water, and contains a first decane compound, a second decane compound, and the like in ppm. The fluorine compound is as shown in Table 1 above.

In Example 1, tetraethoxysilane as a first decane compound, trimethyl hydroxy decane as a second decane compound, and hydrogen fluoride as a fluorine-containing compound were used.

In Example 2, tetrahydroxy decane as a first decane compound, trimethyl hydroxy decane as a second decane compound, and ammonium hydrogen fluoride as a fluorine-containing compound were used.

In Example 3, tetrahydroxy decane as a first decane compound, chlorotrimethylnonane as a second decane compound, and ammonium fluoride as a fluorine-containing compound were used.

In Example 4, 3-aminopropyltrihydroxydecane as a first decane compound, dichlorodimethylsilane as a second decane compound, and ammonium fluoride as a fluorine-containing compound were used.

In Example 5, hexahydroxydioxane as a first decane compound, 1,3-dioxane diol as a second decane compound, and ammonium fluoride as a fluorine-containing compound were used.

Trimethoxy hydroxy hydrazine as the first decane compound was used in Example 6. An alkane, trimethyl hydroxy decane as a second decane compound, and hydrogen fluoride as a fluorine-containing compound.

In Example 7, butyl trihydroxy decane as a first decane compound, trimethyl hydroxy decane as a second decane compound, and hydrogen fluoride as a fluorine-containing compound were used.

In Example 8, tetrahydroxy decane as a first decane compound, chlorotrimethylnonane as a second decane compound, and hydrogen fluoride as a fluorine-containing compound were used.

Comparative example

The composition of the etching solution for the tantalum nitride layer according to the comparative example is shown in Table 2 below.

Each of the etching solutions for the tantalum nitride layer according to Comparative Examples 1 to 4 includes 85% by weight of phosphoric acid and the balance of water, and contains the first decane compound and the fluorine-containing compound in ppm, as in Table 2 above. Shown.

In Comparative Example 1, tetrahydroxy decane as a first decane compound and hydrogen fluoride as a fluorine-containing compound were used.

In Comparative Example 2, tetrahydroxy decane as a first decane compound and ammonium hydrogen fluoride as a fluorine-containing compound were used.

In Comparative Example 3, tetrahydroxy decane as a first decane compound and ammonium fluoride as a fluorine-containing compound were used.

In Comparative Example 4, 3-aminopropyltrihydroxydecane as a first decane compound and ammonium fluoride as a fluorine-containing compound were used.

Experimental result

Various etching solutions for the tantalum nitride layer having the compositions of the examples and the comparative examples were boiled at respective temperatures (145 ° C, 157 ° C, and 165 ° C) for 0.5 hours, 1 hour, and 2 hours, and a tantalum nitride layer The ruthenium oxide layer was etched for 1 minute. The ruthenium oxide layer as the thermally grown oxide layer was etched at a purity of 2 Å/min at 165 ° C in a pure phosphoric acid solution.

The tantalum nitride layer and the tantalum oxide layer were planarized before being placed in the etching solution, wherein the layer was immersed in a hydrofluoric acid dilution prepared by diluting 50% by weight of hydrofluoric acid in a ratio of 200:1 for 30 seconds. The clock is flattened.

Each etching for etching temperature and etching time was completed, and then each etching solution was analyzed with a fineness analyzer, and the average diameter of the cerium-based particles present in the etching solution was measured.

After etching at 165 ° C for 5 minutes, the average etching amount per minute was calculated by an ellipticity meter to determine the etching rate.

The results of the measurements are shown in Tables 3-14 below.

The respective particle diameters of the etching solutions for the tantalum nitride layer having the compositions according to Examples 1 to 8 were analyzed, and as a result, it was confirmed that the ruthenium-based particles were not present in the etching solution or had a very small diameter of 0.01 μm or less. .

In particular, it was confirmed that it is difficult to form the ruthenium-based particles even in the case where the etching solution capable of suppressing the occurrence of particles is boiled for a long time at a high temperature.

Further, as a result of measurement of the etching amount per minute at 165 ° C, even when a fluorine-containing compound was added to the etching solution, it was confirmed that the etching rate was the same as that of pure phosphoric acid.

On the other hand, the particle diameter of the etching solution for the tantalum nitride layer having the composition of Comparative Examples 1 to 4 was analyzed, and as a result, it was confirmed that the ruthenium-based particles each having a diameter of 20 μm or more existed in the following Tables 11-14. In the etching solution shown.

Further, it was confirmed that the amount of etching per minute of the cerium oxide layer was increased by the fluorine-containing compound.

Experimental Example 2. Cleaning solution after etching

Experimental result 1

The tantalum substrate was planarized by immersing it in a solution prepared by diluting 50% by weight of hydrofluoric acid in a ratio of 200:1 for 30 seconds before placing the tantalum substrate including the tantalum nitride layer into the etching solution.

Next, the planarized tantalum substrate was etched using an 85% phosphoric acid aqueous solution containing 500 ppm of tetrahydroxynonane and 500 ppm of ammonium fluoride (NH ₄ F) for 5 minutes, and then washed with 80 ° C each having the composition according to each of the examples and comparative examples. The solution was initially washed for 10 seconds and then washed twice with deionized water for 30 seconds at 80 °C.

The cleaning solution after the preliminary cleaning and the deionized water after the completion of the second cleaning were separately extracted, and the average particle diameter of the cerium-based particles present in the cleaning solution and the deionized water was measured by a fineness analyzer.

Table 15 below shows the compositions of the cleaning solutions of Examples 9 and 10 and Comparative Examples 5 to 7, and the measurement results of the average diameters of the cerium-based particles present in the cleaning solution and the deionized water after washing.

Experimental result 2

Before placing the germanium substrate including the tantalum nitride layer into the etching solution, the germanium substrate is placed The flattening was carried out by immersing in a solution prepared by diluting 50% by weight of hydrofluoric acid in a ratio of 200:1 for 30 seconds.

Next, the planarized ruthenium substrate was etched using an 85% phosphoric acid aqueous solution containing 500 ppm of 3-aminopropyl decanetriol and 500 ppm of ammonium fluoride (NH ₄ F) for 5 minutes, and then each having the composition according to each of the examples and comparative examples. The 80 ° C cleaning solution was initially washed for 10 seconds and then washed twice with deionized water for 30 seconds at 80 ° C.

The cleaning solution after the preliminary cleaning and the deionized water after the completion of the second cleaning were separately extracted, and the average particle diameter of the cerium-based particles present in the cleaning solution and the deionized water was measured by a fineness analyzer.

Table 16 below shows the compositions of the cleaning solutions of Examples 11 and 13 and Comparative Examples 8 to 10, and the measurement results of the average diameters of the cerium-based particles present in the cleaning solution and the deionized water after washing.

Experimental result 3

The tantalum substrate was planarized by immersing it in a solution prepared by diluting 50% by weight of hydrofluoric acid in a ratio of 200:1 for 30 seconds before placing the tantalum substrate including the tantalum nitride layer into the etching solution.

Next, the planarized ruthenium substrate was etched using an 80% phosphoric acid aqueous solution containing 500 ppm of 3-aminopropyl decanetriol and 500 ppm of ammonium fluoride (NH ₄ F) for 5 minutes, and then each having the composition according to each of the examples and the comparative examples. The 80 ° C cleaning solution was initially washed for 10 seconds and then washed twice with deionized water for 30 seconds at 80 ° C.

The cleaning solution after the preliminary cleaning and the deionized water after the completion of the second cleaning were separately extracted, and the average particle diameter of the cerium-based particles present in the cleaning solution and the deionized water was measured by a fineness analyzer.

Table 17 below shows the compositions of the cleaning solutions of Example 14 and Comparative Example 11, and the measurement results of the average diameters of the cerium-based particles present in the cleaning solution and the deionized water after washing.

Experimental result 4

The tantalum substrate was planarized by immersing it in a solution prepared by diluting 50% by weight of hydrofluoric acid in a ratio of 200:1 for 30 seconds before placing the tantalum substrate including the tantalum nitride layer into the etching solution.

Next, the planarized tantalum substrate was etched using an 80% phosphoric acid aqueous solution containing 500 ppm of tetrahydroxynonane and 500 ppm of ammonium fluoride (NH ₄ F) for 5 minutes, and then washed with 80 ° C each having the composition according to each of the examples and comparative examples. The solution was initially washed for 10 seconds and then washed twice with deionized water for 30 seconds at 80 °C.

Extracting the cleaning solution after the preliminary cleaning is completed and after the second cleaning is completed Deionized water was used to determine the average particle size of the cerium-based particles present in the cleaning solution and deionized water by a fineness analyzer.

Table 18 below shows the compositions of the cleaning solutions of Examples 15 and 16 and Comparative Example 12, and the measurement results of the average diameters of the ruthenium-based particles present in the cleaning solution and the deionized water after washing.

Experimental result 5

The tantalum substrate was planarized by immersing it in a solution prepared by diluting 50% by weight of hydrofluoric acid in a ratio of 200:1 for 30 seconds before placing the tantalum substrate including the tantalum nitride layer into the etching solution.

Next, the planarized tantalum substrate was etched using an 80% phosphoric acid aqueous solution containing 500 ppm of tetrahydroxynonane and 500 ppm of ammonium fluoride (NH ₄ F) for 5 minutes, and then at various temperatures each having the composition according to each of the examples and comparative examples. The cleaning solution was initially washed for 10 seconds and then washed twice with deionized water for 30 seconds at 80 °C.

The cleaning solution after the preliminary cleaning and the deionized water after the completion of the second cleaning were separately extracted, and the average particle diameter of the cerium-based particles present in the cleaning solution and the deionized water was measured by a fineness analyzer.

Table 19 below shows the compositions of the cleaning solutions of Examples 17 and 18 and Comparative Examples 13 to 14, and the measurement results of the average diameters of the cerium-based particles present in the cleaning solution and the deionized water after washing.

The etching solution capable of suppressing the occurrence of particles according to the present disclosure may include a decane compound-based cerium additive capable of increasing the selectivity of the cerium nitride layer with respect to the cerium oxide layer, and may further include an etch rate capable of compensating for a decrease due to the use of the cerium additive. Fluorine-containing compound.

Further, the etching solution capable of suppressing the occurrence of particles according to the present disclosure uses different kinds of decane compounds having different numbers of hydrophilic functional groups bonded to ruthenium atoms, and thus can prevent the etch rate of the ruthenium oxide layer due to being in the etching solution There is an excess of fluorine and it increases.

Further, due to the etching solution capable of suppressing the occurrence of particles according to the present disclosure The occurrence of the ruthenium-based particles can be effectively suppressed, and the defects of the ruthenium substrate or the etching device and the cleaning device due to the ruthenium-based particles occurring during the etching or after the post-etch cleaning can be prevented.

In particular, according to the present disclosure, the decane compound represented by Chemical Formula 3 may be substituted with a decyloxy group for the hydroxyl group of the hydroxy group-containing ruthenium particles present in the cleaning solution in a form in which it is impossible to wash the ruthenium substrate after etching. Further polymerization, and thus growth and precipitation of the ruthenium-based particles can be prevented.

Various substitutions, changes and modifications of the above disclosure may be made by those skilled in the art without departing from the scope and spirit of the disclosure. Therefore, the present disclosure is not limited to the above-described exemplary embodiments.

Claims (15)

An etching solution for suppressing the occurrence of particles, comprising: an aqueous solution containing at least one of an inorganic acid and an organic acid; a first decane compound containing 1-6 germanium atoms, wherein at least one germanium atom and three or More hydrophilic functional group bonding; a second decane compound containing 1-6 ruthenium atoms, wherein the number of hydrophilic functional groups bonded to one ruthenium atom is at most 2; and a fluorine-containing compound. An etching solution for suppressing the occurrence of particles according to the above-mentioned claim 1, wherein the inorganic acid is selected from the group consisting of sulfuric acid, nitric acid, phosphoric acid, citric acid, hydrofluoric acid, boric acid, hydrochloric acid, perchloric acid, and phosphoric anhydride. At least one of pyrophosphoric acid and polyphosphoric acid. An etching solution for suppressing the occurrence of particles according to the above aspect of the invention, wherein the organic acid is at least one selected from the group consisting of acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, tartaric acid, and hydrogen carbonate. The etching solution for suppressing the occurrence of particles according to the first aspect of the invention, wherein the hydrophilic functional group is a hydroxyl group or a functional group which may be substituted with a hydroxyl group under the pH condition of the etching solution. An etching solution for suppressing the occurrence of particles according to claim 4, wherein a monofunctional group substituted with a hydroxyl group at a pH of the etching solution is selected from an amino group, a halogen group, a sulfonic acid group, Phosphonic acid group, phosphoric acid group, thiol group, alkoxy group, decylamino group, ester group, acid anhydride group, hydrazine halide group, cyano group, carboxyl group and azole group. An etching solution for suppressing the occurrence of particles according to the first aspect of the invention, wherein the first decane compound is represented by the following Chemical Formula 1 or Chemical Formula 2: In Chemical Formula 1, R ₁ to R ₄ are each independently the hydrophilic functional group, or are selected from the group consisting of hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, and C containing at least one hetero atom. ₂ -C ₁₀ heteroalkyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aromatic Functional groups of alkyl, decyloxy and decane, and In Chemical Formula 2, R ₅ to R ₂₀ are each independently the hydrophilic functional group, or are selected from the group consisting of hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, and C containing at least one hetero atom. ₂ -C ₁₀ heteroalkyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aromatic a functional group of an alkyl group, a decyloxy group, and a decane, and n is an integer of from 1 to 5. The etching solution for suppressing the occurrence of particles according to claim 6, wherein the hydrophilic functional group is selected from the group consisting of a hydroxyl group, an amino group, a halogen group, a sulfonic acid group, a phosphonic acid group, a phosphoric acid group, and sulfur. Alcohol group, alkoxy group, decylamino group, ester group, acid anhydride group, hydrazine halide group, cyano group, carboxyl group and azole group. An etching solution for suppressing the occurrence of particles according to the first aspect of the patent application, wherein The first decane compound has a concentration of 100 to 10,000 ppm in the etching solution. The etching solution for suppressing the occurrence of particles according to the first aspect of the invention, wherein the second decane compound is represented by the following Chemical Formula 3 or Chemical Formula 4: In Chemical Formula 3, R ₁₁ to R ₁₄ are each independently the hydrophilic functional group, or are selected from the group consisting of hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, and C containing at least one hetero atom. ₂ -C ₁₀ heteroalkyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aromatic Functional groups of alkyl, decyloxy and decane, and In Chemical Formula 4, R ₁₅ to R ₂₀ are each independently the hydrophilic functional group, or are selected from the group consisting of hydrogen, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₂ cycloalkyl, and C containing at least one hetero atom. ₂ -C ₁₀ heteroalkyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₁ -C ₁₀ haloalkyl, C ₁ -C ₁₀ aminoalkyl, aryl, heteroaryl, aromatic a functional group of an alkyl group, a decyloxy group, and a decane, and n is an integer of from 1 to 5. An etching solution for suppressing the occurrence of particles according to claim 9, wherein the hydrophilic functional group is selected from the group consisting of a hydroxyl group, an amino group, a halogen group, a sulfonic acid group, a phosphonic acid group, and a phosphoric acid group. Group, thiol group, alkoxy group, decylamino group, ester group, acid anhydride group, hydrazine halide group, cyano group, carboxyl group and azole group. The etching solution for suppressing the occurrence of particles according to the first aspect of the invention, wherein the second decane compound has a concentration of 100 to 30,000 ppm in the etching solution. An etching solution for suppressing the occurrence of particles according to the above aspect of the invention, wherein the fluorine-containing compound is at least one selected from the group consisting of hydrogen fluoride, ammonium fluoride, ammonium difluoride, and ammonium hydrogen fluoride. The etching solution for suppressing the occurrence of particles according to the first aspect of the invention, wherein the fluorine-containing compound is a compound in which one organic cation and one fluorine-based anion are ionically bonded. The etching solution for suppressing the occurrence of particles according to claim 13, wherein the organic cation is selected from the group consisting of alkyl ammonium, alkyl pyrrolidine, alkyl imidazolium, alkyl pyrazolium, alkyl oxazole Anthracene, alkylthiazolium, alkylpyridinium, alkylpyrimidinium, alkylpyridazinium, alkylpyrazinium, alkylpyrrolidinium, alkylhydrazine, alkylmorpholinium and alkylpyridinium . An etching solution for suppressing the occurrence of particles according to claim 13, wherein the fluorine-based anion is selected from the group consisting of fluoride, fluorophosphate, fluoroalkyl-fluorophosphate, fluoroborate, and fluoroalkyl fluoride. Borate.